Vibratory relay



Sept. 26, 1944. s. H. TOWNER 2,358,891

VIBRATQRY RELAY Filed Dec. 21, 1942 CONTROLLED CIRCUIT Patented Sept. 26, 1944 VIBRATORY RELAY Stanley Herbert Towner, London, England Application December 21, 1942, Serial No. 469,724 In Great Britain December 12, 1941 4 Claims.

This invention relates to vibratory relays and to circuits therefor of the type as customarily employed for the generation or transmission of successive impulses as employed in connection with energizing circuits of automatic telephone exchange systems and the like.

The object of the invention is so to improve the circuit of an electromagnetic vibrator that the pulses generated shall be more uniform in their timing. Electromagnetic vibrators of the type with which the present invention is concerned, namely, that in which vibration i maintained by self-interrupting contacts, are subject to variations of the contact or make-to-break ratio, particularly as between the initial impulse and the subsequent impulses. One cause of this variation is that a vibrator of this type has its Winding fully energised before impulsing starts, but after the armature has been released on a first de-energisation of the Winding, the armature continues to vibrate on pulses of current which are controlled by the self-interrupting contact, and Which are of insufficient magnitude to bring the winding back to its former state of complete energisation. Thus the energisation of the winding during the first cycle tends to retard the free movement of the armature and produce distortion on the first impulses. This distortion is extremely diflicult to eliminate by simple adjustment.

The features of the present invention are set out as claims 1, 2, 3 and 4 of the statement of claim with which this specification ends, and the further description of the nature of the invention and the particular description and ascertainment of the manner in which the invention is to be performed will be found in the following taken in conjunction with the accompanying drawing in which Fig. 1 shows a known circuit arrangement; while Fig. 2 shows a circuit arrangement in accord ance with the present invention.

Fig. 3 is a similar view with the start contacts 5| and 52 closed for vibratory operation.

In both cases the armature is shown in its operated position.

Referring firstly to Fig. l which is the known design, it will be seen that prior to impulsing the vibrator magnet VM is fully energised over the series circuit from the battery, resistance RI, magnet VM, contacts S back to earth. When it is desired to start the device into vibration the start contacts S are changed over so that the magnet VM is short-circuited by the circuit from battery, resistance RI, vibratory contact V, front contact S, resistance R2, to earth. Being short circuited the magnet VM will release in a time determined by the extent of its original energisation. On release the vibratory contacts V will drop off, removing the short-circuit and permitting the magnet to re-energise. In this second and subsequent energisations the vibrator magnet VM is only able to energise momentarily and does not again reach the condition of full energisation in which it was found orignally. Because of this difference the make-to-break ratio is afiected.

In Fig. 2 this shortcoming is removed. Prior to impulsing, the vibrator magnet VM is energised in a circuit consisting of a battery, resistance RI, start contact SI, magnet winding VM, start contact S2, to earth. The value of resistance BI is such as under the non-vibrating position of the start contacts as shown in Fig. 2 the current magnitude is suificient to energize the magnet VM for holding its movable contact armature against the influence of the spring s. When impulsing is to commence the start contacts Si and S2 are changed over, as shown in Fig. 3, and the magnet is short-circuited by the circuit consisting of earth, contacts V, resistance R2, to battery. Under this condition, as shown in Fig. 3, the value of resistance R2 is such as to determine a current magnitude insufficient to hold the contact armature against the influence of its spring so as to close the controlled circuit through V, S2, VM and S1 to ground and likewise from the battery, resistance R2 and magnet coil to ground.

When the winding is thus re-energized it is in the opposite direction from that of the nonvibrating position of Fig. 1. As will be understood with the shorting of the resistance of R2 by closing of the controlled circuit, the magnitude of the current thru the coil will energize the magnet to overcome the spring s.

The reverse energisation does not affect the armature until the remaining flux resulting from initial energisation has been overcome. During this interval the armature will release fully and produce an undistorted impulse of the impulsing contact.

What is claimed is:

1. An electro-magnetic vibrator circuit device comprising a vibrator magnet having a movable contact armature and an energizing coil, direct current holding circuit means operative normally to energize the coil for holding the armature in non-vibrating position and an actuating circuit'means adapted to efiect self-imerrupting operation of the armature, said actuating circuit means being connected to the coil to efiect energizing thereof in opposite polar relation to that of the holding circuit means and a switch arranged to insert the coil into one or the other of the circuit means.

2. An electro-magnetic vibrator circuit system comprising a vibrator magnet having a movable contact armature and an energizing coil, direct current holding circuit mean normally operative for holding the armature inoperative, an actuating circuit means adapted to eiTect self-interrupting operation of the armature, said actuating circuit means being connected to the coil in opposite polar relation to that of the holding circuit, a direct current source for the actuating circuit and means to insert the coil into the holding circuit, or into the actuating circuit. 7

3. An electro-magnetic vibrator circuit system comprising a vibrator magnet having a movable contact armature and an energizing ,coil, a controlled circuit having a contact engaged by the armature, resilient means normally to close the armature on said contact, direct current holding circuit means normally operative for holding the armature inoperative against the influence of the resilient means, an actuating circuit means adapted to efiect self-interrupting operation of the armature, said actuating circuit means being connected to the coil in opposite polar relation to that of the holding circuit, a direct current source for the actuating circuit and means to insert the coil into the holding circuit or into the actuating circuit.

4. An electro-magnetic vibrator circuit device comprising a vibrator having a movable contact armature and an energizing coil, a controlled circuit, a direct current holding circuit means operative normally to hold the armatur inoperative, an actuating circuit means adapted to effect self-interruption of the armature and including a battery, resistance and connections therefrom to ground throughthe coil and armature in parallel relation, said actuating circuit means being connected to the coil in opposite polar relation to that of the holding circuit, said circuit connections providing that closing of the controlled circuit will be efiected inseries with the coil and in shorting relation to the resistance and means for inserting the coil into the holding circuit or into the actuating circuit.

STANLEY HERBERT TOWNER. 

